The present invention relates to a method for manufacturing an organic electroluminescent device using a liquid-phase process, an organic electroluminescent device manufactured by the method, and an electronic apparatus.
Organic electroluminescent (EL) devices using organic matters have been developed as self light-emitting displays that can replace liquid crystal displays at an accelerated rate in recent years. Examples of methods for manufacturing such organic EL devices that have been proposed include providing low molecules by a vapor-phase process such as evaporation and providing polymers by a liquid-phase process. See Applied Physics Letters, Vol. 51 (12), 21 Sep. 1987, p. 913, and Applied Physics Letters, Vol. 71 (1), 7 Jul. 1997, p. 34, for example.
Polymer organic EL elements are less reliable than low-molecular organic EL elements. Although this reliability difference is mainly attributed to differences in the rate of developing materials between the two, the above-mentioned process difference is considered to be another factor. Specifically, liquid-phase processes have shortcomings, such as essentially easy mixing of impurities and the low concentration of liquid-phase films, making ion diffusion more likely than in cases with evaporated films. To address these problems, various methods have been employed to reduce impurities and other ions. Here, a method using titanium oxide particles is adopted to block metal ions that are considered to diffuse from an electrode. Japanese Unexamined Patent Application Nos. 4-150369 and 2001-179890 are examples of related art in which titanium oxide is introduced into an organic EL element, although they produce different results.